2 pounds halibut fillet, cut into equal pieces
— Kosher salt
— Black pepper in a mill
3 tablespoons olive oil or butter
8 garlic cloves, slivered
1 small leek, white part only, cut into thin rounds
1 small carrot, cut into small dice
12 very small new potatoes, quartered
1 small zucchini, cut into small dice
6 cups fish fumet
2 cups aioli
1 tablespoon minced fresh Italian parsley
1 tablespoon minced fresh chives
3 or 4 basil leaves, cut into very thin ribbons
½ baguette, thinly sliced, lightly toasted
Preheat the oven to 250 degrees.
Season the halibut all over with salt and pepper.
Heat the olive oil or butter in a large, deep skillet set over medium-high heat. When the pan is hot, add the fillets and sauté for 2 minutes; turn and sear 2 minutes more. Transfer the fillets to a plate.
Reduce the heat to medium-low, add the garlic, leek and carrots and sauté until they begin to soften, about 6 minutes. Season with salt and pepper. Add the potatoes, sauté for 2 minutes, add the zucchini and squash, toss together with the other vegetables and season with salt and pepper. Add the fish fumet, increase the heat to medium and simmer 5 minutes. Taste the potatoes and if they are not tender, simmer 2 to 3 minutes more. Taste the broth and correct the seasoning. Use a ladle to transfer 1 cup of the broth to a small bowl.
Return the fish to the pot, reduce the heat to low, cover and simmer 5 minutes.
Meanwhile, set aside a generous 1/3 cup of aioli. Whisk 2 tablespoons of the reserved broth into the remaining aioli until the mixture is smooth. Add 2 tablespoons more, mix again, and repeat, until all of the broth has been mixed into the aioli.
Transfer the fish fillets into individual soup plates. With the heat on very low, stir the tempered aioli and the fresh herbs into the broth and vegetables. Do not under any circumstances let the mixture simmer or boil. Remove from the heat.
Slather the reserved aioli over the toasted baguettes. Ladle broth and vegetables over each portion of fish, garnish with baguette slices and serve immediately.